May 27, 2026
Frank Calegari, professor and associate chair of the Department of Mathematics, and Young-Kee Kim, the Albert A. Michelson Distinguished Service Professor in the Department of Physics and the Enrico Fermi Institute, have been elected to the Fellowship of the Royal Society, the UK’s national academy of sciences.
Since its founding in 1660, the Royal Society’s purpose has been to recognize, promote, and support excellence in science and encourage the development and use of science for the benefit of humanity.
This year, over 90 researchers from around the world in all areas of science, engineering, and medicine were elected Fellows or Foreign Members of the Society for their outstanding contributions to science.
“Our Fellowship is strengthened not only by individual distinction, but by the diversity of perspectives and experiences its members bring,” said Sir Paul Nurse, President of the Royal Society. “This incoming cohort highlights the truly international character of contemporary science and underscores the vital role that plays in achieving breakthroughs that benefit us all.”
Frank Calegari
Frank Calegari’s research focuses on the area of algebraic number theory. He is particularly interested in the Langlands program, a set of mathematical ideas that has been called the "grand unified theory of mathematics.”
In 2021, Calegari and two colleagues discovered a groundbreaking proof of what’s known as the unbounded denominators conjecture. In 2024, he and his collaborators created a new technique to prove certain numbers are irrational—significantly improving upon the previous method, which had been around since the 1970s.
Calegari is a member of the American Academy of Arts and Sciences, a fellow of the American Mathematical Society, and a recipient of an American Institute of Mathematics Fellowship, a Sloan Fellowship, and a Simons Fellowship in Mathematics. He was a plenary speaker at the 2022 International Congress of Mathematicians and received the 2026 AMS Frank Nelson Cole Prize for Number Theory.
Young-Kee Kim
Much of Young-Kee Kim’s research seeks to understand the origin of mass for elementary particles—the most fundamental constituents of matter—through the Higgs mechanism, using the world’s highest-energy colliders.
Kim has made seminal contributions to precision measurements of the W boson and top quark masses at Fermilab’s CDF experiment, and subsequently to studies of Higgs boson properties, including its decay modes and self-interactions, at CERN’s ATLAS experiment. Her research is guided by the principle that a comprehensive understanding of the Higgs mechanism requires the synthesis of these complementary measurements.
Kim, who served as co-leader of the CDF experiment in 2004–2006 and President of the American Physical Society (APS) in 2024, is an elected member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the Korean Academy of Science and Technology. She is also a fellow of the APS, the American Association for the Advancement of Science, and the Alfred P. Sloan Foundation. She received the Ho-Am Prize, the Arthur L. Kelly UChicago Faculty Prize, and the Korean American Pioneer Award.
“Professor Calegari has built mathematical bridges with striking originality, and Professor Kim has made great strides in understanding how fundamental particles acquired mass,” said Ka Yee C. Lee, dean of the Physical Sciences Division at the University of Chicago. “We are delighted that the Royal Society has recognized their vital contributions to their fields.”